KR960007891B1 - Beam compressor - Google Patents

Abstract

This shuffled type optical compressor converts serial optical bit stream multiplexed(n:1) by a bit unit to serial optical bit stream multiplexed(n:1) by a multi bit(r-bits) unit. The shuffled type optical compressor consists of : a reversing multiplexing system(31) for multiplexing an optical or an electronic input signal in parallel(1:nxr), an optical delayers(32-32n) outputting the signal from the reverse multiplexer(31) with a delaying time determined by OD(i)=(r-1)*(n*T-t), where 1 Di Dn, t is a value according to an optical short pulse generation technique, and r is the number of bit stream ; and an optical coupler(33) for coupling the parallel signal from the optical delayers(32-32n) and outputting in nxr:1.

Description

Shuffle Optical Compressor

1 is a diagram illustrating input and output optical bit strings of a conventional optical compressor.

2 is a conceptual diagram of a shuffle optical compressor for explaining the present invention.

3 is a view showing an embodiment of an n × r shuffle optical compressor according to the present invention.

Figure 4 is an illustration of a projection of the shuffle optical compressor according to the present invention.

* Explanation of symbols for main parts of the drawings

31: demultiplexer 32 to 32n: optical fiber delay line

33: optical coupler

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shuffled type optical compressor, which is a kind of optical functional devices applied in optical systems.

1 is a diagram illustrating input and output optical bit strings of a conventional optical compressor.

As shown in the drawing, the conventional optical compressor is intended only for temporal compression of an optical bit stream, so that the number of optical bits is extruded at a compression rate for application to a system. No function was provided with respect to the order inside the compressed optical bit string. In general, when a bitwise multiplexed serial optical bitstream passes through a routing device such as a photoelectric space switch, the electrical switching speed of the device for relocation must be faster than the bit rate of the multiplexed serial optical bitstream, i.e. If only one bit is multiplexed to each channel, the routing rate of the routing element should be equal to the multiplexed bit rate. The current compression technology of optical bit sequence photoelectric Pico Massachusetts (picosecond: 10 ^-12 sec), but to the compression unit to below, in the case of the path of the photoelectric switch element for the designated area of the vent or the like Gwanggyo nanoseconds (nanosecond: 10 ⁹ sec) Since the switching time is required, there is a problem in that it is impossible to effectively use a vast amount of optical resources.

In order to solve the above problems, the present invention provides a multiplexed serial optical bit string (n × r bit strings) inputted in units of bits (1 bit), and thus, multiple bit units (r optical bit strings included in the same channel). Transformed into a serialized multiplex optical bit stream, n times compressed r-bits per time slot, and the remaining time domain without compressed optical bits facilitates the addition of r: 1 multiplexing. Bits are additionally compressed at the same compression rate (k times) to increase the time between multiple bits to provide switching time for the path redistribution device, providing a shuffle optical compressor, an optical matching function device that matches the entire n × r bit strings. Its purpose is to.

In order to achieve the above object, the present invention, in the optical compression device that is an optical functional element, demultiplexing means for demultiplexing the signal input in the form of light and electron in 1: n × r parallel, the reverse of the demultiplexing means Delay time of multiplexed output signal OD (i) = (r-1) × (n × Tt) 1in, t: dependence on light's short pulse generation technique, r: number of bit strings And an optical coupler for combining and outputting a plurality of optical fiber delay means and an n × r parallel output signal delayed through each of the plurality of optical fiber delay means. It is characterized by.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

2 is a conceptual diagram of a shuffle optical compressor according to the present invention.

As shown in the figure, the concept of a shuffle optical compressor is a serialized multiplexed (n: 1) serialized bitstream (speed vbps) multiplexed in units of bits (n: 1). The conversion to the optical bit string is processed by the shuffle method.

The bit sequence of the transformed sequence is r times compressed and k times each of the n timeslots in the compressed optical bit sequence.

To physically embody this concept, first convert the input-deal serial optical bits in parallel through a (n × r) time demultiplexer and add a certain amount of fiber lines to each output. (N × r): 1 Use an optocoupler or the like to make an OR connection.

The optical fiber delay values are summarized in Equation (1). The value of these fiber delay lines is a mathematical expression that deals with the conceptual method.

Where T is the inverse of the bit rate v, and OD (n) is the delay value of the optical fiber delay line to be added to the nth output of the multiplexer.

And t

This is the time interval between bits in the optical bit string in the time slot where compression is finally completed. This time interval t is a value depending on the short pulse generation technique of light.

At this time, the output optical bit string is defined as a time domain in which n × r bits are compressed within n / v time of the total n × r / v time and have data (see time axis of FIG. 2), and the rest (r-1 (R−1) × n / v time, which is) unit time, is empty as a time domain without data. So it can be used for the next multiplexing. Here, the r bits for each channel ch1 to chn are arranged in series in a 1 / (r × v × k) second interval in the data string in the time domain where data is present. The time of r bits per channel grouped by this time interval is 1 / (v × k), and the remaining (1-1 / k) v is the remaining free time Tm in the time slot of the channel. The Tm in this time slot can be used up during the switching time of the photonic space switch, which is the routing element.

Referring to the above method as an example, a 2x4 shuffle optical compressor with k = 3.2, n = 2, r = 4, a bit string of 155Mbps with a bit rate multiplexing of data of channels A and B is 1: 8 ( 2x4) are converted in parallel through a multiplexer, and then pass through each optical fiber delay line. When the interval between the final compressed optical bits is 0.5ns, the fiber delay values are shown in the table below.

The spare time Tm at this time is (1-1 / 3.2) / (155M) = 4.4 (ns). In addition, the inter-bit spacing of the optical bits in the final compressed same timeslot is 500 ps.

3 is a block diagram of a shuffle optical compressor according to the present invention, wherein 31 is an inverse multiplexer, 32 to 32n is an optical fiber delay line, and 33 is an optical coupler.

As shown in the figure, the shuffle-type optical compressor has a demultiplexer 31 for demultiplexing a signal input in the form of light or electron in a 1: n × r parallel, and the demultiplexed output signal of the demultiplexer 31. To n × r: 1 by combining n × r parallel output signals delayed through each of the optical fiber delay lines 31 to 32n and the optical fiber delay lines 32 to 32n. It consists of an optical coupler 33 for outputting.

Figure 4a is an embodiment of using a shuffle optical compressor (OSAC) according to the present invention for the time-space-time (TST) which is a typical structure of the circuit switch, Figure 4b is a detailed view of the input and output pattern, 41 41-4 are 2: 1 multiple expansion, 42-42-4 are shuffle-type optical compressors, 43-43-4 are optical fiber delay lines, and 45 are optical couplers, respectively.

(B) of FIG. 4b shows the input light bit string of channels 1 to 8, (b) shows the input light bit string of each shuffle optical compressor, and (c) shows the output light bit string of each shuffle optical compressor. Indicates. And (d) shows the final output bit string past the delay line and the combiner.

As shown in the drawing, the TST using the shuffle optical compressor (OSAC) uses a 2 × 4 shuffle optical compressor using a 2-by-1 bit multiplexed bit stream (multiplexing rate 155 Mb / s, see also FIG. 4b). In the same channel, the four bits of the mountain although gathered in one time slot unit produce an output of k times compressed shape (Fig. 4b (c)). When combined with a 4: 1 optical coupler, these data use 43 to 43-4 optical fiber delay lines to prevent data collisions and to arrange them in the time-free region of each data. Each delayed value is shown in Fig. 4b. As specified (this is a temporal distribution for 4: 1 simple multiplexing).

As described above, it serves as a suitable optical matching device that provides the necessary time for the operation of the optical switching system or various optical systems.

In the present invention as described above, in the design of the optical exchange system and another optical system, it is possible to process the limit time of the photoelectric device, etc. in the spare time (Tm), there is an effect that can maintain the high compressibility of the optical pulse train as it is. .

Claims (1)

In an optical compressor, which is an optical functional element, demultiplexing means (31) for demultiplexing a signal input in the form of light and electron in a 1: n × r parallel, and demultiplexing the output signal of the demultiplexing means (31). OD (i) = (r-1) × (n × Tt) (1in, t: dependence on light's short pulsegeneration technique, r: number of bit strings) Optical coupler for combining n × r parallel output signals delayed through each of the optical fiber delay means 32 to 32n and the plurality of optical fiber delay means 32 to 32n. Shuffle-type optical compressor characterized in that it comprises a (33).